Complementarity and cooperation in international criminal justice

This research paper examines legal gaps in the international criminal justice system, specifically regarding the obligation of states to exercise national jurisdiction and the lack of a horizontal framework for interstate cooperation. It assesses two intergovernmental initiatives—the International Law Commission (ILC) study on crimes against humanity and the Belgium, Slovenia, and Netherlands (BSN) initiative—aimed at enhancing complementarity by establishing conventions for mutual legal assistance and the obligation to prosecute or extradite.

• The International Criminal Court (ICC) is designed as a court of last resort based on the principle of complementarity, meaning national criminal justice systems are intended to be the primary vehicles for accountability for international crimes.
• A significant legal gap exists because the Rome Statute does not legally obligate states parties to establish national jurisdiction over Rome Statute crimes, even though domestic criminalisation is essential for effective complementarity.
• There is a legal gap regarding horizontal interstate cooperation; while the Rome Statute mandates vertical cooperation between states and the ICC, it does not require states to cooperate with one another to investigate international crimes.
• The International Law Commission (ILC) is working toward a convention on crimes against humanity that would require states to criminalise these crimes in national law and exercise universal jurisdiction if the accused is present in their territory.
• The ILC project aims to establish robust interstate cooperation, including mutual legal assistance, extradition, and the principle of aut dedere aut judicare (the obligation to prosecute or extradite).
• The Belgium, Slovenia, and Netherlands (BSN) initiative is broader than the ILC project, seeking a procedural multilateral treaty on mutual legal assistance and extradition covering genocide, war crimes, and crimes against humanity.
• The BSN initiative faces a strategic dilemma regarding its forum; while it aims for maximum universal reach, linking it too closely to the ICC's Assembly of States Parties might discourage ratification by states with political objections to the ICC, particularly in Africa.
• The author suggests that the ILC and BSN initiatives are not necessarily mutually exclusive and could be synergistic, combining the ILC's rigorous legal drafting with the BSN's state-led political momentum.
• Filling the 'impunity gap' through these conventions could help mitigate tensions between the African Union (AU) and the ICC by enabling African states to prosecute international criminals independently.

APA

Tladi, D. (2014). Complementarity and cooperation in international criminal justice. Institute for Security Studies. https://issafrica.s3.amazonaws.com/site/uploads/Paper277V2.pdf

Chicago

Tladi, Dire. Complementarity and cooperation in international criminal justice. Institute for Security Studies, 2014. https://issafrica.s3.amazonaws.com/site/uploads/Paper277V2.pdf.

Wikipedia

{{cite report |last1=Tladi |first1=Dire |title=Complementarity and cooperation in international criminal justice |publisher=Institute for Security Studies |date=November 2014 |url=https://issafrica.s3.amazonaws.com/site/uploads/Paper277V2.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{tladi2014complementarity, author = {Tladi, Dire}, title = {{Complementarity and cooperation in international criminal justice}}, institution = {Institute for Security Studies}, year = {2014}, month = nov, url = {https://issafrica.s3.amazonaws.com/site/uploads/Paper277V2.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }